PURIFICATION OF ACID PHOSPHATASE FROM GINGER (ZINGIBER OFFICINALE) RHIZOMES

Acid phosphatase has been obtained from the rhizomes in an apparently homogenous form following ammonium sulphate (60%) fractionation, DEAE-cellulose ion exchange chromatography and sephadex G-100 gel filtration. The final step in the purification on sephadex G-100 gel filtration provided an yield of 27% with 5.8 fold purification of the enzyme. Acid phosphatase isolated by the purification procedure described here appears to be homogeneous by PAGE, SDS-PAGE and gel filtration on G-200. The specific staining for the enzyme activity gave a single band corresponding to protein staining by coomassie blue or silver. The molecular weight of acid phosphatase was determined to be 46kDa by SDS-PAGE and on sephadex G-200 gel filtration, the enzyme gave a molecular weight of 45.5kDa , a value very close to that of obtained by SDS-PAGE. The enzyme was found to be a monomeric protein active at pH 5.6 and temperature 400C preferentially using sodium ?-glycerophosphate as the substrate.